Appendage-resident epithelial cells expedite wound healing response in adult zebrafish.

Adult zebrafish are able to heal large-sized cutaneous wounds in hours with little to no scarring. This rapid re-epithelialization is crucial for preventing infection and jumpstarting the subsequent regeneration of damaged tissues. Despite significant progress in understanding this process, it remains unclear how vast numbers of epithelial cells are orchestrated on an organismic scale to ensure the timely closure of millimeter-sized wounds. Here, we report an unexpected role of adult zebrafish appendages (fins) in accelerating the re-epithelialization process. Through whole-body monitoring of single-cell dynamics in live animals, we found that fin-resident epithelial cells (FECs) are highly mobile and migrate to cover wounds in nearby body regions. Upon injury, FECs readily undergo organ-level mobilization, allowing for coverage of body surfaces of up to 4.78 mm2 in less than 8 h. Intriguingly, long-term fate-tracking experiments revealed that the migratory FECs are not short-lived at the wound site; instead, the cells can persist on the body surface for more than a year. Our experiments on "fin-less" and "fin-gaining" individuals demonstrated that the fin structures are not only capable of promoting rapid re-epithelialization but are also necessary for the process. We further found that fin-enriched extracellular matrix laminins promote the active migration of FECs by facilitating lamellipodia formation. These findings lead us to conclude that appendage structures in regenerative vertebrates, such as fins, may possess a previously unrecognized function beyond serving as locomotor organs. The appendages may also act as a massive reservoir of healing cells, which speed up wound closure and tissue repair.

Current state of iodine nutrition in Filipino school-aged children.

OBJECTIVES: Globally, although progress in eliminating iodine deficiency disorders (IDD) has been reported, IDD is still considered to be a global health problem. As school-aged children are the most accessible population group, their urinary iodine (UI) concentration data are accepted and used as an indicator of IDD for the general population. The aim of this study was to reassess the national, regional, and provincial estimates of UI as a measure of IDD among Filipino school-aged children. METHODS: Casual urine samples were collected from 22 588 children, 6 to 12 y of age, from participating households in the eighth National Nutrition Survey. UI was determined based on the catalytic action of iodine in the Sandell-Kolthoff reaction and IDD was evaluated using criteria from the World Health Organization, United Nations Children's Fund, International Council for Control of Iodine Deficiency Disorders criteria. RESULTS: The median UI level among Filipino school-aged children was 168 µg/L, corresponding to optimal iodine nutrition; whereas 23.2% had UI reflective of excessive iodine intake. Cjildren in the Zamboanga Peninsula Region had median UI level of 68 µg/L and 41.1% of participants had UI values <50 µg/L, which is indicative of mild iodine deficiency. Children from Guimaras and Zamboanga del Norte, or 2.4% of the provinces, had moderate iodine deficiency. CONCLUSION: Although the median UI level of school-age children was optimal, there are pockets of inadequacy and excessive intake that need special concern for targeted intervention.

Iron absorption from NaFeEDTA-fortified oat beverages with or without added vitamin C.

BACKGROUND: Food fortification is the best long-term approach for reducing the incidence of iron deficiency. OBJECTIVE: To determine iron absorption from NaFeEDTA-fortified oat beverages without and with vitamin C. MATERIALS AND METHODS: Iron absorption in 19 apparently healthy 6-year-old children was studied. Two oat beverages fortified with iron (labeled with stable isotopes of NaFeEDTA), zinc, and vitamin A, without and with vitamin C was consumed in two consecutive days in random order. Blood samples were taken 14 days later for stable isotope measurements. RESULTS: The mean fractional iron absorption from the fortified oat beverage without vitamin C (5.65 ± 0.54%) was significantly lower than that from the beverage with vitamin C (7.14 ± 0.90%; p < 0.05). CONCLUSION: Fortified oat beverages may offer a convenient and effective mechanism to improve the iron status of children. The addition of vitamin C improved iron absorption by an additional 1.5%.